On a Long Term Evolution Advanced (LTE-A for short) communications system, a Low Power Node (LPN for short) is introduced, where the low power node and a macro cell node together form a heterogeneous network. On the heterogeneous network, the main purposes of the low power node are: to enhance coverage, increase capacity, improve communication quality of an edge user, enhance group mobility and temporary network deployment, reduce costs, and the like. The introduction of the low power node changes an original typology of the communications system, and therefore it has a practical significance for studying new features in a heterogeneous network scenario.
A process of performing a cell handover by a terminal (also called a User Equipment, UE for short) is as follows: For example, a source macro cell node, that is, a source base station, sends a handover command to the terminal; after receiving the handover command, the terminal sends a random access request to a target macro cell node, that is, a target base station; the target base station receives the random access request sent by the terminal, allocates a resource required by the terminal during communication in a target macro cell to the terminal, and sends corresponding configuration information of the resource to the terminal by using a Random Access Response (RAR for short); and the terminal receives the RAR and performs resource reconfiguration for the target macro cell according to configuration information carried in the RAR, thereby completing a handover of the terminal from a source macro cell to the target macro cell.
For a co-channel Heterogeneous Network (Het-net for short), because a low power node is introduced, co-channel interference exists between a macro cell node and the low power node. Because of co-channel interference between a neighboring macro cell node and the low power node, a failure probability of RAR transmission is relatively high, which results in a relatively high failure rate of performing a cell handover by a terminal.